Decorators attach definition metadata to Python classes and register it in a
TypeRegistry. The schema builder starts from operation roots and resolves fields,
arguments, interfaces, union members, enum values, and scalar mappings.
Annotation resolution handles built-in Python types, decorated classes, lists,
optionals, forward references, and explicit FastQL wrappers. The compiler applies
GraphQL names and nullability, then creates the corresponding internal named types.
Schema builds a type map by traversing roots and additional named types. Duplicate
GraphQL names that refer to different definitions are rejected. Reachable output and
input references are collected recursively, including abstract type members.
The compiled schema owns default directives, root type references, the complete type
map, and schema configuration. SDL, introspection, validation, and execution all read
from this object.
